The invention relates generally to medical apparatus and particularly to apparatus for mechanically applying rhythmic pressure to a patient's chest in order to maintain artificial circulation. The mechanical apparatus provided to maintain the circulation of a person whose heart has stopped beating are driven ordinarily by electric motors, compressed air, gas and in some cases manually. Such apparatus ordinarily provides a generally planar horizontal surface on which the patent is strapped underneath a plunger which depresses the sternum in the center of his chest 11/2 to 2 inches at a regular rate.
A serious problem exists with respect to such apparatus in that improper positioning of the patient in the device or slippage after initial positioning of the patient such as may readily occur when the patient is being moved on a stretcher with the apparatus attached or when the apparatus is used in a moving ambulance. In extreme cases the ambulance may traverse a bumpy road or even have an accident resulting in movement of the patient. This movement of the patient will result in substantial pressure being applied to portions of the patient's chest other than the lower sternum and in some cases has caused great damage such as broken ribs, punctured lungs, heart and throat injuries, etc., in addition to interrupting the process of cardiac resuscitation and the creation of artificial circulation. The interruption aspect may be potentially even more dangerous than the other injuries. The problem is compounded in that usually the attendants who are operating the machine are extremely busy tending to various other problems with the patient or with other patients and may not recognize the existence of the problem for a finite time interval which is longer than the time in which substantial injury to the patient may occur.
It is an object of the invention to provide apparatus which will enable the operator to quickly and easily define a predetermined region on a patient over which the plunger will apply a force.
It is another object of the invention to provide apparatus which will either turn the resuscitator off or sound an alarm or both.
It is still another object of the invention to provide apparatus which is simple and inexpensive to manufacture and use.